The present invention relates to accumulators of the type which are used to store mechanical energy. More specifically, the present invention relates to accumulators which store energy using a compressed gas.
Accumulators are a type of energy storage device which are used to store mechanical energy in the form a compressed gas. Recently, interest in accumulators has grown because they can be used in fuel efficient cars whereby energy which may be lost during the braking activity can be stored and subsequently reused.
Energy storage devices for liquid power applications that are significantly more compact than existing ones will enable energy regeneration for many applications, including fluid power hybrid vehicles and construction equipment. One approach to hydraulic energy storage makes use of a compressed gas enclosed in a closed chamber. As the system must contain the expanded gas and the hydraulic oil which is displaced, the optimal energy density occurs at a relatively modest expansion ratio resulting in a small energy density.